Automatic lumber feeder



Sept. 8, 1964 w. H. RAMBO AUTOMATIC LUMBER FEEDER 2 Sheets-Sheet 1 Filed Dec. 1l, 1961 INVENTOR W/LL/A/Vl H. RA/l//BO Sept. 8, 1964 W. H. RAMBO AUTOMATIC LUMEER FEEDER Filed Deo. 11, 1961 2 Sheets-Sheet 2 IN V EN TOR.

United States Patent O "ce 3,147,342 AUTOMATIC LUMBER FEEDER William H. Rambo, Portland, Oreg.; The Bank of California, National Association, executor of said Rambo, deceased Filed Dec. 11, 1961, Ser. No. 153,434 10 Claims. (Cl. 198-33) This invention relates to automatic lumber feeders.

I have constructed a feeder having rotary cams for lifting a series of boards in successive fashion over stationary stop means, with a view of feeding the boards from the feeder to an associated apparatus, such as a trimmer, in regularly spaced transversely disposed fashion. One difficulty with this feeder is that when a short board is stopped by the stop means, a long board just behind the short board will be urged against the short board and the projecting portion of the long board will be urged to move forwardly to cant the long board. The projecting portion will thus engage the stop means in advance of the remainder of the long board and be lifted over the stop means before the intended time to leave the board askew and partially across the stop means to foul up the feeding operation. The long board will also adversely affect the boards following it to materially interfere with proper feeding.

It is a main object of the present invention to provide a feeder overcoming the above defects, and specifically to provide in such a feeder auxiliary stop means to prevent improper feeding of a long board and to assure its proper position at the time it is fed from the feeder.

Various other objects of the invention will be apparent from the accompanying drawings wherein:

FIG. l is a plan view of a feeder of the present invention;

FIG. 2 is a vertical section on an enlarged scale taken along line 2-2 of FIG. l;

FIG. 3 is a perspective view of an auxiliary stop assembly;

FIG. 4 is a fragmentary plan view of a stationary stop unit and associated cam, on a scale larger than FIG. l;

FIG. 5 is a vertical section taken along line 5-5 of FIG. 4;

FIG. 6 is a fragmentary plan View of a switch assembly;

FIG. 7 is a vertical section taken along line '7-7 of FIG. 6;

FIG. 8 is a fragmentary plan view of an auxiliary stop unit;

FIG. 9 is a vertical section taken along line 9 9 of FIG. 8; and

FIG. l0 is a vertical section showing the auxiliary stop assembly in lowered condition.

Referring to FIG. l, the feeder has six feeder chains 11 reeved around a set of sprockets 13 fixedly mounted on a shaft 15 and also reeved around a set of sprockets 17 fixedly mounted on an idle shaft 19. The shaft 15 is driven by a prime mover not shown so that the upper reaches of the chains move upwardly (forwardly) as the parts are shown in FIG. 1. The shaft 19 is driven by the chains 11, and another set of fixed sprockets Z1 on the shaft 19 drive a set of feed-in chains 22, which feed a series of boards to the feeder chains 11. There are also a plurality of feedout chains Z3 reeved around sprockets 24 on the shaft 15.

Three boards are shown on the chains 11 and identified as B1, B2 and B3. The boards have been arranged previously with one set of ends thereof, the right-hand set as the parts are shown in FIG. l, against a guide 25 which is supported by an open framework only part of which is shown in FIG. l and designated generally by the letter F.

The upper reach of each of the feeder chains 11 is sup- 3,147,842 Patented Sept. 8, 1964 ported by a guide member 31 in the form of a channel and best shown in FIG. 2. The guide members are supported on the framework F.

Also mounted on the framework are a plurality of stationary board stop units 33 which are in lateral alignment. A unit is shown in detail in FIG-S. 4 and 5 and includes an elongated stop member 35 resting on a support strip 37 and having at one end an upstanding stop element 39 and at its opposite end an ear 41 having a stud 43. The stud extends through an ear 45 on the strip 37 and has nuts 47 to provide for longitudinal adjustment of the position of the stop member 35 relative to the strip 37. Slot and bolt type connections 49 (FIG. 4) securely hold the stop member in any position of adjustment.

The strip 37 is supported at its ends on the framework F by pivots 51 and S3, the latter having a stud 55 received through the strip. Nuts 57 on the stud provide for vertical adjustment of the strip 37 and thus the stop element 39, to dispose the stop element in a desired relationship to the level L of the lower surfaces of the boards being handled.

Associated with each stop unit is a board lifting cam 61, the cams being mounted on a shaft 63 journaled on the framework F and driven by a source not shown. The cams function to lift a board to a height greater than that of the stop elements 39 and to impart forward movement to the board to push it over the stop elements.

It is apparent from FIG. l that the short board B has engaged two stop units 33 to have its movement arrested. Board B2 has been shoved against board Bl and the continued forward push of the chains 11 on the portion of the board B2 projecting beyond board B1 has canted the board B2 and also the following board B3. Were it not for certain structure to be now described, it is apparent that when the cams 61 lifted the board B1 over the stop units 33, they would also lift the left-hand ends of the boards B2 and B3 over the associated stop units 33 to foul up the feeding operation and leave the boards B2 and B3 in askew positions.

Associated with each of the two left-hand stop units 33 in FIG. 1 is an auxiliary stop assembly generally indicated by the reference numeral 71. An assembly is best shown in FIG. 3, its relationship to a stop unit 33 best shown in FIG. 2, and its detail construction best shown in FIGS. 6-10. FIGS. 8 and 9 show the details of an auxiliary stop unit which includes a base member 73 (FIG. 9) pivoted at one end at 75 on the framework F and adapted to have its other end moved upwardly or downwardly by a double-acting air cylinder 77 pivoted at 79 to the framework.

An auxiliary stop member 81 is adjustably connected at 83 (FIG. S) to the base member 73 and has at one end a stop element 85 and at its lother end a longitudinal adjustment device 87.

The operation of each air cylinder is controlled by its own switch `assembly shown in FIGS. 6 and 7, the switch assembly controlling a solenoid valve 88 (FIG. 3) which supplies air to and exhausts air from the cylinder. Referring to FIG. l, each switch assembly is located to the right of its auxiliary stop unit 71 for a purpose to appear.

A switch assembly includes a pair of spaced mounting pieces 91 (FIG. 6) adjustably ysecured to the framework F and pivotally supporting .a trip member 93 (FIG. 7) by means of a pivot shaft 95. A weight 97 urges the trip member 93 to move counterclockwise, and an adjustable stop 99 engages a mounting piece 91 to limit such movement and dispose a slanted board engaging portion 101 of the trip member ina desired position relative to the level L of the lower surfaces of the boards being handled.

It is apparent that because of its slanted surface, the

3 trip member has contact with a board for a distance greater than the width of a board, and in the range of one and one-half to two times the width of a board depending on the relative dimensions of the trip member and boards being handled. The importance of this will be explained shortly.

The trip member is recessed at its bottom rear edge to accommodate the roller of a trip arm 163 of a microswitch 105. The switch is secured at 107 to a support plate 109 for vertical adjustment to enable adjustment of the cycle of operation of the air cylinder. When the trip member 93 is in the up position (its normal position), the switch 105 affects the solenoid valve so that air is supplied to the cylinder to raise the piston therein (and thus the auxiliary stop element 85), whereas if the trip member is depressed by a board, the switch 105 controls the solenoid Valve to reverse the supply of air to the cylinder to move the stop element to a lowered position as shown in FIG. l0. FIGS. 9 and 10 show the relationship of the auxiliary stop element and trip member 93 to the level L of the work.

Operation FIG. 2 shows the height relationship of the following to each other; a stationary stop element 39 of a unit 33, a stop element S5 of a unit 71, a trip member 93, the level L of the work, a cam 61 in full lines in its nonlifting position, and in dotted lines in its lifting position.

It is evident that the cam in the latter position can lift a Y board over the stop element 39 but not over the stop element 85.

Now, referring to FIG. l, it is apparent that if the high spots on the two right-hand cams 61 commence lifting the short board over the two right-hand stationary stop units 33, the two left-hand cams will tend to lift the left-hand ends of the askew boards B2 and B3 over the twolefthand stop units 33. However, the trip members 93 will not be engaged by the boards B2 and B3, and thus the auxiliary stop units of the assemblies 71 will be raised to prevent such action, without, of course, preventing the board B1 from being lifted over the associated stationary stop units 33. Thus board B1 is deposited on the feeder chains 11 beyond the various stops and fed to the feed out chains 23. The latter have spaced lugs 113 for carrying the boards in successive fashion to an appropriate mechanism, such as a trimmer.

Although the left-hand ends of the boards B2 and B3 are arrested by the auxiliary stops, the right-hand ends are now free to move and are moved forwardly under the influence of the feeder chains 11 to bring the board B2 against the associated stationary stops. Thus the board is once again brought to a position at right angles to the direction of feed. Board B3 is similarly positioned for similar reasons, but if board B3 is slightly canted because of the action of the chains 11 on the portions projecting beyond the board B2, it will be subsequently straightened.

As the board B2 assumes its correct position, it will engage both trip members 93 to depress them to cause the auxiliary stops to be lowered. Thus when the cams 61 lift the board B2 the board is moved over the stationary stops and deposited therebeyond. The continued contact of the board B2 and the trip members 93 holds the auxiliary stops down until the board is beyond them.

Referring to FIG. l, if the board B2 were longer, the left-hand end thereof would engage the trip member 93 to lower the left-hand auxiliary stop 71. However, the machine would still work properly, because the left-hand end of the board B3 would not be located forwardly enough to allow it to move over the left-hand stops 33 and 71.

As a safety measure for machines of different dimensions, the switches 105 preferably are connected in series so that all switches must be closed in order to lower the CFI auxiliary stops. Thus closure of one switch only, would not result in lowering its auxiliary stop.

Having described the invention in what is considered to be the preferred embodiment thereof, it is desired that it be understood that the invention is not to be limited other than by the provisions of the following claims.

I claim:

1. An automatic lumber feeder comprising:

feeding means for feeding boards of the same or different length along a predetermined path, with said boards extending generally transversely of said path,

a series of stops located in transverse aligned relation with respect to said path and engageable with such boards to temporarily arrest movement thereof, whereby when a short board is against certain of said stops, an immediately following longer board, which is in an askew position relative to such stops, may have an end portion against one of the remaining stops at the same time that such short board is against said certain of said stops,

means for lifting boards over said stops in successive fashion whereby under the above circumstances a short board and the end portion of a longer board may be simultaneously lifted over said stops to cause said longer board to assume a position where part of it is over said stops and part is not,

auxiliary stop means located in transverse alignment with said stops for engaging the end portions of longer boards and preventing them from being lifted over the stops associated with such end portions,

and inactivating means for inactivating said auxiliary stop means whenever a longer board is against and is parallel to said stops, whereby an end portion of an askew longer board will be prevented from being lifted over the associated stop until said longer board is parallel to and against said stops.

2. An automatic lumber feeder comprising:

feeding means for feeding boards of the same or different length along a predetermined path, with said boards extending generally transversely of said path,

said feeding means frictionally engaging said boards and operating without interruption during a period of operation of said feeder to constantly urge boards 4along said path,

a series tof stops located in transverse aligned relation with respect to said path and engageable with such boards to temporarily arrest movement thereof, whereby when a short board is against certain of said stops, an immediately following longer board, which is in an askew position relative to such stops, may have an end portion against one of the remaining stops at the same time that such short board is against said certain of said stops,

means for lifting boards over said stops in successive fashion whereby under the above circumstances a short board and the end portion of a longer board may be simultaneously lifted over said stops to cause said longer board to assume a position where part of it is over said stops and part is not,

auxiliary stop means loc-ated in transverse alignment with said stops for engaging the end portions of longer boards and preventing them from being lifted over the stops associated with such end portions,

said feeding means causing an askew longer board to assume a parallel position against said stops after a preceding short board has been lifted over said stops,

and inactivating means for inactivating said auxiliary stop means whenever a longer board is against and is parallel to said stops, whereby an end portion of an askew longer board will be prevented from being lifted over the associated stop until said longer board is parallel to and 'against said stops.

3. An automatic lumber feeder comprising:

feeding means for feeding boards of the same or different length along a predetermined path, with said boards extending gener-ally transversely of said path,

guide means for engaging one end of each board for alignment purposes,

a series of stops located in transverse aligned relation with respect to said path and engageable with such boards to temporarily arrest movement thereof, whereby when a short board is against certain of said stops, an immediately following longer board, which is in an askew position relative to such stops, may have an end portion against one of the remaining stops at the same time that such short board is against said certain of said stops,

means for lifting boards Iover said stops in successive fashion whereby under the above circumstances a short board and the end portion of a longer board may be simultaneously lifted over said stops to cause said longer board to Vassume a position where part of it is over said stops and part is not,

auxiliary stop means located in transverse alignment with said stops for engaging the end portions of longer boards and preventing them from being lifted over the stops associated with such end portions,

said auxiliary stop means being located so that there are at least two stops between said auxiliary stop means and said guide means,

and inactivating means for inactivating said auxiliary stop means whenever a longer board is against and is parallel to said stops, whereby an end portion of an askew longer board will be prevented from being lifted over the associated stop until said longer board is parallel to and against said stops.

4. An automatic lumber feeder comprising:

feeding means for feeding boards of the same or different length along fa predetermined path, with said boards extending generally transversely of said path,

guide means for engaging one end of each board for alignment purposes,

a series of stops located in transverse aligned relation with respect to said path and engageable with such boards to temporarily arrest movement thereof, whereby when a short board is against certain of said stops, an immediately following longer board, which is in an askew position relative to such stops, may have an end portion against one of the remaining stops at the same time that such short board is -against said certain of said stops,

means for lifting boards over said stops in successive fashion whereby under the above circumstances a short board and the end portion of a longer board may be simultaneously lifted over said stops to cause said longer board to assume a position where part of it is over said stops and part is not,

auxiliary stop means located in transverse alignment with said stops for engaging the end portions of longer boa-rds and preventing them from being lifted over the stops associated with such end portions,

said auxiliary .stop means being located so that there are at least two stops between said auxiliary stop means and said guide means,

and inactivating means for inactivating said auxiliary stop means whenever a longer board is against and is parallel' to said stops, whereby an end portion of an askew longer board will be prevented from being lifted over the associated stop until said longer board is parallel to and against said stops,

said inactivating means including sensing means located between said auxiliary stop means and said guide means, and engaged by a longer board when such longer board assumes a position parallel to and against said stop.

5. An `automatic lumber feeder comprising:

feeding means for feeding boards of the same or different length along a predetermined path, with said boards extending generally transversely of said pat-h,

a series of stops located in transverse aligned relation with respect to said path and engageable with such boards to temporarily arrest movement thereof, whereby when a short board is against certain of said stops, an immediately following longer board, which is in askew position relative to such stops, may have an end portion against one of the remaining stops at the same time that such short board is against said certain of said stops,

means for lifting boards over said stops in successive fashion whereby under the above circumstances a short board and the end portion of a longer board may be simultaneously lifted over said stops to cause said longer board to assume a position where part of it is over said stops and part is not,

auxiliary stop means located in transverse alignment with said stops for engaging the end portions of longer boards and preventing them from being lifted over the stops associated with such end portions,

said auxiliary stop means being higher than said stops in the activated position of said `auxiliary stop means,

andV inactivating means for inactivating said auxiliary stop means whenever a longer board is against and is parallel to said stops, whereby an end portion of an -askew longer board will Ibe prevented from being lifted over the associated stop until said longer board is parallel to and against said stops.

6. An automatic lumber feeder comprising:

feeding means for feeding boards of the same or different length along a predetermined path, with said boards extending generally transversely of said path,

a series of stops located in transverse aligned relation with respect to said path and engageable with such boards to temporarily arrest movement thereof, whereby when a short board is against certain of said stops, an immediately following longer board, which is in an askew position relative to such stops, may lh-ave an end portion against one of the remaining stops at the same time that such short board is against said certain of said stops,

means for lifting boards over said stops in successive fashion whereby under the above circumstances a short board and the end portion of a longer board may be simultaneously lifted over said stops to cause said longer board to assume a position where part of it is over said stops and part is not,

auxiliary stop means located in transverse alignment with said stops for engaging the end portions of longer boards and preventing them from being lifted over the stops associated with such end portions,

said auxiliary stop means being lhigher than said stops in the activated position of said auxiliary stop means,

and inactivating means for inactivating said auxiliary stop means whenever a longer board is against and is parallel to said stops, whereby an end portion of an askew longer board will be prevented from being lifted over `the associated stop until said longer board is parallel to and against said stops,

said inactivating means inactivating said auxiliary stop means by causing the latter to assume a lowered position.

7. An automatic lumber feeder comprising:

feeding means for feeding boards of the same or different length along a predetermined path, with said boards extending generally transversely of said path,

said feeding means frictionally engaging -said boards and operating without interruption during a period of operation of said feeder to constantly urge boards along said path,

guide means for engaging one end of each board for alignment purposes,

a series of stops located in transverse aligned relation with respect to said path and engageable with such boards to temporarily arrest movement thereof, whereby when a short board is against certain of said stops, an immediately following longer board, which is `in an askew position relative to such stops, may have an end portion against one of the remaining stops at the same time that such short board is against said certain of said stops,

means for lifting boards over said stops in successive fashion whereby under the above circumstances a short board and the end portion of a longer board may be simultaneously lifted over said stops to cause said longer board to assume a position where part of it is over said stops and part is not,

auxiliary stop means located in transverse alignment with said stops for engaging the end portions of longer boards and preventing them from being lifted over the stops associated with such end portions,

said feeding means causing an askew longer board to assume a parallel position against said stops after a preceding short board has been lifted over said stops,

said auxiliary stop means being located so that there t are at least two stops between said auxiliary stop means and said guide means,

said auxiliary stop means being higher than said stops in the activated position of said auxiliary stop means,

and inactivating means for inactivating said auxiliary stop means whenever a longer board is against and is parallel to said stops, whereby an end portion of an askew longer board will be prevented from being lifted over the associated stop until said longer board is parallel to and against said stops,

said inactivating means including sensing means located between said auxilialy stop means and said guide means, and engaged by a longer board when such longer board assumes a position parallel to and against said stop,

said inactivating means inactivating said auxiliary stop means by causing the latter to assume a lowered position.

8. An automatic lumber feeder comprising:

feeding means for feeding boards of the same or different length along a predetermined path, with said boards extending generally transversely of said path,

said feeding means frictionally engaging said boards and operating without interruption during a period of operation of said feeder to constantly urge boards along said path,

guide means for engaging one end of each board for alignment purposes,

a series of stops located in transverse aligned relation with respect to said path and engageable with such boards to temporarily arrest movement thereof, whereby when a short board is against certain of said stops, an immediately following longer board, which is in an askew position relative to such stops, may have an end portion against one of the remaining stops at the same time that such short board is against said certain of said stops,

means for lifting boards over said stops in successive fashion whereby under the above circumstances a short board and the end portion of a longer board may be simultaneously lifted over said stops to cause said longer board to assume a position where part of it is over said stops and part is not,

auxiliary stop means located in transverse alignement with said stops for engaging the end portions of longer boards and preventing them from being lifted over the stops associated with such end portions,

said feeding means causing an askew longer board to assume a parallel position against said stops after a preceding short board has been lifted over said stops,

said auxiliary stop means being located so that there are at least two stops between said auxiliary stop means and said guide means,

and inactivating means for inactivating said auxiliary stop means whenever a longer board is against and is parallel to said stops, whereby an end portion of an askew longer board will be prevented from being lifted over the associated stop until said longer board is parallel to and against said stops.

9. An automatic lumber feeder comprising:

feeding means for feeding boards of the same or different length along a predetermined path, with said boards extending generally transversely of said path,

said feeding means frictionally engaging said boards and operating without interruption during a period of operation of said feeder to constantly urge boards along said path,

guide means for engaging one end of each board for alignment purposes,

a series of stops located in transverse aligned relation with respect to said path and engageable with such boards to temporarily arrest movement thereof, whereby when a short board is against certain of said stops, an immediately following longer board, which is in an askew position relative to such stops, may have an end portion against one of the remaining stops at the same time that such short board is against said certain of said stops,

means for lifting boards over said stops in successive fashion whereby under the above circumstances a short board and the end portion of a longer board may be simultaneously lifted over said stops to cause said longer board to assume a position where part of it is over said stops and part is not,

auxiliary stop means located in transverse alignment with said stops for engaging the end portions of longer boards and preventing them from being lifted over the stops associated with such end portions,

said feeding means causing an askew longer board to assume a parallel position against said stops after a preceding short board has been lifted over said stops,

said auxiliary stop means being located so that there are at least two stops between said auxiliary stop means and said guide means,

and inactivating means for inactivating said auxiliary stop means whenever a longer board is against and is parallel to said stops, whereby an end portion of an askew longer board will be prevented from being lifted over the associated stop until said longer board is parallel to and against said stops,

said inactivating means including sensing means located between said auxiliary stop means and said guide reans, and engaged by a longer board when such longer board assumes a position parallel to and against said stop.

l0. An automatic lumber feeder comprising:

feeding means for feeding boards of the same or different lengths along a predetermined path, with said boards extending generally transversely of said path,

said feeding means frietionally engaging said boards and operating without interruption during a period of operation of said feeder to constantly urge boards along said path,

guide means for engaging one end of each board for alignment purposes,

a series of stops located in transverse aligned relation with respect to said path and engageable with such boards to temporarily arrest movement thereof, whereby when a short board is against certain of said stops, an immediately following longer board, which is in an askew position relative to such stops, may have an end portion against one of the remaining stops at the same time that such short board is against said certain of said stops,

means for lifting boards over said stops in successive fashion whereby under the above circumstances a short board and the end portion of a longer board may be simultaneously lifted over said stops to cause said longer board to assume a position v/liere part of it is over said stops and part is not,

auxiliary stop means located in transverse alignment with said stops for engaging the end portions of longer boards and preventing them from being lifted over the stops associated with such end portions,

said feeding means causing an askew longer board to assume a parallel position against said stops after a preceding short board has been lifted over said stops,

said auxiliary stop means being located so that there are at least two stops between said auxiliary stop means and said guide means,

said auxiliary stop means being higher than said stops in the activated position of said auxiliary stop means,

and inaetivating means for inactivating said auxiliary stop means whenever a longer board is against and is parallel to said stops, whereby an end portion of an askew longer board will be prevented from being lifted over the associated stop until said longer board is parallel to and against said stops,

said inactivating means including sensing means located between said auxiliary stop means and said guide means, and engaged by a longer board when such longer board assumes a position parallel to and against said stop.

References Cited in the le of this patent UNITED STATES PATENTS 2,403,673 Mead July 9, 1946 2,679,919 De Koning June 1, 1954 2,731,130 Blickenderfer Jan. 17, 1956 2,980,234 De Koning Apr. 18, 1961 

1. AN AUTOMATIC LUMBER FEEDER COMPRISING: FEEDING MEANS FOR FEEDING BOARDS OF THE SAME OR DIFFERENT LENGTH ALONG A PREDETERMINED PATH, WITH SAID BOARDS EXTENDING GENERALLY TRANSVERSELY OF SAID PATH, A SERIES OF STOPS LOCATED IN TRANSVERSE ALIGNED RELATION WITH RESPECT TO SAID PATH AND ENGAGEABLE WITH SUCH BOARDS TO TEMPORARILY ARREST MOVEMENT THEREOF, WHEREBY WHEN A SHORT BOARD IS AGAINST CERTAIN OF SAID STOPS, AN IMMEDIATELY FOLLOWING LONGER BOARD, WHICH IS IN AN ASKEW POSITION RELATIVE TO SUCH STOPS, MAY HAVE AN END PORTION AGAINST ONE OF THE REMAINING STOPS AT THE SAME TIME THAT SUCH SHORT BOARD IS AGAINST SAID CERTAIN OF SAID STOPS, MEANS FOR LIFTING BOARDS OVER SAID STOPS IN SUCCESSIVE FASHION WHEREBY UNDER THE ABOVE CIRCUMSTANCES A SHORT BOARD AND THE END PORTION OF A LONGER BOARD MAY BE SIMULTANEOUSLY LIFTED OVER SAID STOPS TO CAUSE SAID LONGER BOARD TO ASSUME A POSITION WHERE PART OF IT IS OVER SAID STOPS AND PART IS NOT, AUXILIARY STOP MEANS LOCATED IN TRANSVERSE ALIGNMENT WITH SAID STOPS FOR ENGAGING THE END PORTIONS OF LONGER BOARDS AND PREVENTING THEM FROM BEING LIFTED OVER THE STOPS ASSOCIATED WITH SUCH END PORTIONS, AND INACTIVATING MEANS FOR INACTIVATING SAID AUXILIARY STOP MEANS WHENEVER A LONGER BOARD IS AGAINST AND IS PARALLEL TO SAID STOPS, WHEREBY AN END PORTION OF AN ASKEW LONGER BOARD WILL BE PREVENTED FROM BEING LIFTED OVER THE ASSOCIATED STOP UNTIL SAID LONGER BOARD IS PARALLEL TO AND AGAINST SAID STOPS. 